There exist numerous machines, and in particular machines actuated by the insertion of coins, tokens, or similar items, where the machine includes a housing closed by a front door. The door includes various items, in particular items required for receiving coins and for issuing a ticket, etc., in return, and also display devices, e.g. liquid crystal devices or filament devices. In normal use, the display system serves to provide a user with a certain amount of information, in particular concerning the actions that need to be performed in order to obtain a given service or on the amount of money that still needs to be inserted into the machine prior to the service being delivered.
Inside the housing of the machine, there are various components, including those which serve for delivering goods or services after money or money's worth has been inserted, and also various electronic circuits for controlling the machine overall. These electronic circuits which control the operation of the machine, e.g. issuing a ticket in response to coins being inserted up to a predetermined amount, make use of various different parameters. For example, for a parking meter, one of the parameters is the price of a parking unit, or in a machine which delivers various different types of goods, one of the parameters is the price of the goods selected by the user. Clearly it is necessary for operatives to be able to change these parameters during maintenance operations in order to adapt a machine to new operating conditions. However, it is also essential to ensure that the means for modifying these parameters are not accessible to users.
In order to understand the problem which the present invention seeks to solve, reference is made to accompanying FIGS. 1 and 2 which are simplified diagrams respectively of the front face of a dispenser of tickets for pay car parking, and a horizontal section through the front face on a line II--II in FIG. 1. FIG. 1 shows a door 10 mounted in the front face of the housing 12 of the machine by means of hinges 14 and 16. The door 10 essentially includes a display system 18, e.g. of the liquid crystal type or of the filament type, a coin slot 20, a slot 22 for issuing printed tickets, a coin return chute 24, and various pushbuttons such as 26 enabling a user to select various different machine functions.
With reference now to FIG. 2, it can be seen that the door 10 which provides mechanical protection for the housing also includes a window 30 with the display device 18 per se being disposed behind the window. The inside face of the door 10 also carries various electronic circuits 32 and a controlling keypad 34. The keypad 34 is used, in particular, during commissioning or maintenance operations for programming the circuits 32 so that the machine provides the required services, for testing the operation of the machine, or for obtaining various items of statistical information concerning machine utilization.
The results of tests or of keying-in new parameters or of making adjustments to the machine can be checked solely by observing the information which appears on the display 18. It will readily be understood that with the prior art configuration shown in FIGS. 1 and 2, it is difficult to check adjustments in this way since the displayed information can be seen only from in front of the door whereas the items used for making the adjustments, i.e. the keypad 34, are to be found on the back face of the door. It should be recalled that it is essential for the display system 18 to be visible from the outside since it serves in normal use for providing users with information, and that the controlling keypad 34 must necessarily be on the inside face of the door in order to prevent unauthorized users from changing the operating parameters of the machine.
In order to remedy these drawbacks, an object of the invention is to provide a structure for a door including a display device, in particular for machines actuated by inserting coins, which enables maintenance, tests, or adjustment operations to be performed under conditions which are improved over those described above.